From owner-freebsd-net@FreeBSD.ORG Mon Mar 8 10:24:33 2004 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 08A2416A4CE; Mon, 8 Mar 2004 10:24:33 -0800 (PST) Received: from postal3.es.net (postal3.es.net [198.128.3.207]) by mx1.FreeBSD.org (Postfix) with ESMTP id E3B7F43D1F; Mon, 8 Mar 2004 10:24:32 -0800 (PST) (envelope-from oberman@es.net) Received: from ptavv.es.net ([198.128.4.29]) by postal3.es.net (Postal Node 3) with ESMTP (SSL) id IBA74465; Mon, 08 Mar 2004 10:24:32 -0800 Received: from ptavv (localhost [127.0.0.1]) by ptavv.es.net (Tachyon Server) with ESMTP id 4FA6D5D08; Mon, 8 Mar 2004 10:24:31 -0800 (PST) To: Andre Oppermann In-reply-to: Your message of "Sun, 07 Mar 2004 23:50:11 +0100." <404BA723.C8141806@freebsd.org> Date: Mon, 08 Mar 2004 10:24:31 -0800 From: "Kevin Oberman" Message-Id: <20040308182431.4FA6D5D08@ptavv.es.net> cc: David Malone cc: freebsd-net@freebsd.org cc: freebsd-current@freebsd.org Subject: Re: My planned work on networking stack X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Mar 2004 18:24:33 -0000 > Date: Sun, 07 Mar 2004 23:50:11 +0100 > From: Andre Oppermann > Sender: owner-freebsd-current@freebsd.org > > David Malone wrote: > > > > On Mon, Mar 01, 2004 at 11:18:34PM +0100, Andre Oppermann wrote: > > > [] automatically sizing TCP send buffers to achieve optimal performance > > > over a wide range of bw*delay situations. (in progress) > > > > Hi Andre, > > > > This reminded me - do you know what happened to the plan to implement > > SACK for FreeBSD? I'm working with a research group that's interested > > in new high speed TCP techniques and they'd prefer to work with > > FreeBSD, but they've been using Linux 'cos they need SACK. They > > might actually be interested in spending some time implementing it, > > if we weren't going to be clashing with anytone else. > > I don't know of any current project or effort to implement SACK on > FreeBSD. It is not on my todo list and it doesn't fit there. But > I'm available if someone wants to discuss specifics and implementation > details. I know that our organization would love to see SACK. Much of the high-performance network development that used to be on FreeBSD has moved to Linux simply because SACK is essential. You can't run trans-oceanic TCP streams of gigabit or more throughput without it. Unfortunately, SACK is often looked upon as a waste of effort to those who use nets in more commercial forms where aggregation of lots of small streams is how fat pipes are used. Research big science are about the only ones who have a real need for this kind of performance and it's growing fast. Without SACK, FreeBSD will be a non-starter for these purposes. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634